Set MAC address to default

Question

Sometimes I need to spoof MAC address, I'm doing so with this command:

ip link set dev eth0 address XX:XX:XX:XX:XX:XX

Is there a way how to set MAC address back to default without reboot?

Answer 1

See also:

sudo ethtool -P eth0

So, to set the MAC address back to its default (assuming GNU grep here):

set_to_real() (
  for i do
    mac=$(ethtool -P "$i" | grep -iEom1 '([0-9a-f]{2}:){5}[0-9a-f]{2}') &&
      ip link set dev "$i" address "$mac"
  done
)
set_real eth0

Answer 2

Your "real MAC" might be reported by the kernel on boot, so have a look at

dmesg | grep eth0

and try using your ip link set... with the MAC you find there.